FIGURE 2.

Neurotrophins and their receptors are expressed in brain tumor-initiating cells. A–C, total RNA was isolated from BTICs, cDNA was synthesized, and RT-PCR analysis was performed for neurotrophin receptors, such as TrkA (A) or TrkB, TrkC, and p75NTR (B), and also for neurotrophic factors NGF, BDNF, and NT3 (C); actin was used as an internal control. Human brain total RNA was used as positive control (+ve). D, TrkA expression was not detected by RT-PCR, quantitative PCR analysis was conducted, and expression of TrkA levels was calculated as ΔΔCt against the actin, an internal control. G179 cells express TrkA were used as a positive control (7) (n = 3 independent experiments; p < 0.05). E, lysates from BTICs were subjected to Western blot analysis for TrkB and TrkC with actin as a loading control. T, truncated receptor; FL, full-length receptor. The data are representative of three independent experiments.